Why do you mainly use amethyst?

All stones naturally emit FIR radiant heating rays when they are hot.

Amethyst is considered the main stone because when preheated, it emits rays in the range from 5 to 14 microns, with the most of energy concentrated at 2 peaks at 7 and 12 microns wavelength. 

This range is considered compatible, so we use amethyst as a main crystal for Far Infrared Rays generation in our mats. 

Our amethyst is a natural chemically untreated crystal that is crushed to 3-10 mm size and tumbled to flatten the sharp edges. 

Korean Ereada® mats may contain some of the most expensive and rare Korean amethyst, but most A or A+ grade crystals are imported from Brazil, where the main world mines are located. We double test all incoming materials at Korean Gemology Labs to ensure that the quality of crystals is ‘A’ grade or higher.